The HPMC (hydroxypropyt methyl cellulose) has been taken as an additive, which retard the setting of cement. The cement-HPMC mixes were prepared having improved compressive strength, tensile strength and fracture toughness in comparison to ordinary Portland cement at late curing ages. The heat of hydration of different cement-HPMC mixes show that the lower contents of HPMC interact with hydrated cement at early curing while higher content at late. The cement-HPMC mix has been found to have better corrosion resistance than OPC in H2SO4, HCl and sea-water. Spectroscopic studies suggested that HPMC bind with free lime. X-ray diffractrogram of 91 days hydrated cement-HPMC mix displays some new peaks as well as few peaks appeared with low intensities showing interaction of HPMC with hydrated cementitious phases.